EP1368934A1 - Systeme, procede et noeud de mesure pour determiner une valeur de numerotation de pire eventualite dans un reseau multiposte - Google Patents

Systeme, procede et noeud de mesure pour determiner une valeur de numerotation de pire eventualite dans un reseau multiposte

Info

Publication number
EP1368934A1
EP1368934A1 EP02700502A EP02700502A EP1368934A1 EP 1368934 A1 EP1368934 A1 EP 1368934A1 EP 02700502 A EP02700502 A EP 02700502A EP 02700502 A EP02700502 A EP 02700502A EP 1368934 A1 EP1368934 A1 EP 1368934A1
Authority
EP
European Patent Office
Prior art keywords
node
gap
measuring
count
worst case
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP02700502A
Other languages
German (de)
English (en)
Inventor
Antonio E. Salloum Slazar
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Koninklijke Philips Electronics NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Koninklijke Philips Electronics NV filed Critical Koninklijke Philips Electronics NV
Priority to EP02700502A priority Critical patent/EP1368934A1/fr
Publication of EP1368934A1 publication Critical patent/EP1368934A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/40—Bus networks
    • H04L12/40052—High-speed IEEE 1394 serial bus
    • H04L12/40078—Bus configuration
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/40—Bus networks
    • H04L12/40052—High-speed IEEE 1394 serial bus
    • H04L12/40084—Bus arbitration
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/64—Hybrid switching systems
    • H04L12/6418—Hybrid transport
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00—Traffic control in data switching networks
    • H04L47/10—Flow control; Congestion control
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00—Traffic control in data switching networks
    • H04L47/10—Flow control; Congestion control
    • H04L47/13—Flow control; Congestion control in a LAN segment, e.g. ring or bus
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00—Traffic control in data switching networks
    • H04L47/10—Flow control; Congestion control
    • H04L47/28—Flow control; Congestion control in relation to timing considerations
    • H04L47/283—Flow control; Congestion control in relation to timing considerations in response to processing delays, e.g. caused by jitter or round trip time [RTT]

Definitions

  • the invention relates to a method for providing dynamic gap optimization for a bus system, and in particular for an IEEE 1394-1995 bus, or IEEE 1394 for short.
  • IEEE 1394 defines a serial bus for use with various home electronics devices.
  • the method of the present invention should allow users and engineers to set up home networks with variable sizes as being based on such bus system.
  • a home network may comprise quite diverse items, such as audio- video sets, Personal Computers, surveillance cameras, household appliances, and other, and as such will be liable to frequent changes, such as through the adding or removing of one of the stations.
  • the inventive method should allow the use of state-of-the-art 1394-standardized stations without requiring extensive computational complexity for its implementation.
  • the bus standard has its traffic effected in data packets, that can be sent through the cabled connection in a collision-free fashion when abiding certain rules of access.
  • the traffic will be controlled through a mechanism that provides so-called gaps, which each define an interval of time during which the bus must remain idle.
  • gaps which each define an interval of time during which the bus must remain idle.
  • the intended origin station in question listens to the existing bus traffic, and checks for the occurrence of a suitable gap as compared to an applicable gap_count.
  • the stations are interconnected according to a logical tree topology. This is one of the reasons that the length of a particular gap, as measured by the various stations, may have widely different values: in fact, the physical distances between the various stations may be quite non-uniform. Non-adherence by a station to the prescribed gap length may cause data packet overlap or data loss, which may be associated to sometimes catastrophic consequences.
  • the above standard allows to avoid these and other problems through specifying a minimum gap_count that immediately relates to a time delay that must be gone before a next packet can be transmitted, cf. Table 1. By in practice amending the actual value of this delay parameter, the listening gap can either be extended for still better avoiding collisions, or rather shortened for more efficiently using available bandwidth.
  • the optimum value of the gap is commensurate with a particular physical construction of the inter-station connection for each of the so-called hops, that are the immediate physical interconnections between the stations.
  • an interconnection cable of 4.5 meters length has been broadly standardized for implementing a hop.
  • the inventor has recognized a need for more flexibility. This would first apply to using other suitable interconnection media for the hops.
  • the hops may be made faster through choosing a smaller length.
  • a longer cable allows interconnection to a far-away station, such as one lying between 4.5 meters and a few tens of meters away.
  • a particular reason for requiring flexibility is to allow effecting a reconfiguration of the network.
  • the inventor has recognized that in a real-time instance of such network the delays may in principle have widely and dynamically variable values, so that any prespecifying procedure would be inferior to a heuristic determination of actually occurring delays.
  • the invention is characterized according to the characterizing part of Claim 1.
  • the measuring of the return trip delay from a single root node to all leaf nodes a fast and reliable procedure is attained, that will approximately yield the optimum travel time value.
  • the invention also relates to a multi-station system arranged for implementing a method as claimed in Claim 1, and to an apparatus arranged for operating as a measuring node in a method as claimed in Claim 1. Further advantageous aspects of the invention are recited in dependent Claims.
  • Figure 1 a general binary tree network for use with the invention
  • Figure 2 a typical network for use with the invention
  • Figure 3 a subaction process for determining a Round Trip Delay (RTD) value
  • Figure 4 a flow chart of the operation
  • the dynamic gap count optimization of the present invention is implemented in a two-step algorithm: first, the maximum value of the round-trip delay is determined, and subsequently, the gap count is calculated from the measured value of the measured maximum value of the Round Trip Delay.
  • Measuring the maximum value of the round trip delay in a given network must be done according to an ad-hoc procedure after the initialization phase of the network in question has already been started.
  • the longest value of such round-trip delay will generally come from a path that directly or indirectly interconnects two leaf -nodes of the tree.
  • the embodiment will thus need some procedure for systematically evaluating and comparing the measured delay values.
  • An ad-hoc procedure may have the logical map of the network contained in the root node. The measurement procedure will then generally also be executed by this root node.
  • two registers may then be available to the bus manager: a first one to load the actually highest value for the Round Trip Delay, and a second one to validate this highest value.
  • Figure 1 illustrates a general binary tree network for use with the invention.
  • root node 20 has a map of the logical network.
  • other nodes 22 through 40 are interconnected in such manner that each node has zero, one or two connected nodes in a higher network layer.
  • Nodes 24, 26, 34, 36 and 40 are leaf nodes in that they connect no node at a higher layer level. In principle, higher numbers for the interconnection multiplicity are feasible.
  • Persons skilled in the art will recognize that exactly the same network may be represented in a different manner, such as by starting from another node as the root node. After an initialization phase, the leaf nodes and root node will have been identified.
  • the bus manager node can be any node of the network with the required facilities in terms of memory. From the topology map, the root node will be able to read the identity of leaf nodes and will proceed to send an asynchronous data packet with no data to every leaf in a consecutive mode.
  • Figure 2 illustrates a typical network for use with the invention in a consumer electronics environment.
  • the nodes accommodate the following functions.
  • Root node 50 has an SetTop Box (STB) Function.
  • Leaf nodes 52, 54, 58 have Personal Computer, Television set and Digital VHS functions, respectively.
  • Non-leaf node 56 likewise has a Television set functionality. Nodes of various different character may be included into in the network of Figure 2.
  • STB SetTop Box
  • FIG. 3 illustrates a subaction process for determining a Round Trip Delay (RTD) value.
  • the STB root node
  • the subaction process will include an automatic acknowledge as an essential element that will be sent back by the receiving leaf node after the required acknowledge gap.
  • A is the Arbitration time
  • P the Data Prefix time
  • E the Data End time.
  • a similar time value may be estimated by determining the difference between the acknowledge arrival time and the packet delivery time, whilst excluding the contributions from data end, acknowledge gap, and data prefix.
  • the overhead values are indeed constants given by the 1394 standard that can be loaded locally into the root node and be subsequently used during the above calculations.
  • the root node recursively registers the measured round trip delay for every leaf node. In the example of Figure 2, three values will be registered.
  • S is the set of leaf nodes.
  • the value obtained is loaded into a given register of the bus manager and a validation register is set, in order to indicate that the determination has been made. All procedures at the root node can be implemented in C code based on an available '1394 stack.
  • the bus manager While the validation register has not yet been set, the bus manager continues to wait for the measured maximum RTD. When the validation register is set, the bus manager reads the value of RTD and calculates the gap count using
  • AT is an additional timing due to the internal delay in the leaf nodes and can be estimated as 308 ns, and ceiling ( ) rounds the argument to the nearest integer toward infinity.
  • such an equation can be included in the C- language code of the used application to replace Table 1.
  • the Bus manager compares the gap count with the calculated value and in case of need will send the calculated value to every node.
  • the dynamic gap count optimization can be applied in current 1394 compliant products by using the available stack, topology map, subaction process, bus manager, etc. It solves the problem of a variable size network allowing larger flexibility to the final user.
  • arbitration reset gap, arb__res_gap be greater than the subaction gap, subact_gap, under a worst case condition.
  • BR max 98.314 Mbit/s is the maximum base rate in the bus.
  • the arb_res_gap seen by one leaf node (A) must be always greater than the subaction gap seen by the other leaf node (B).
  • the B leaf node sees the subaction gap as the sum of four terms, namely the maximum subaction delay, the maximum arbitration delay, the maximum RTD and an additional timing due to internal delay in the leaf nodes.
  • subact_gap maX subact_delay max + arb_delay max + RTD ma ⁇ + AT (6)
  • Figure 4 illustrates a flow chart of the operation.
  • the operation starts, and all necessary hardware and software facilities are assigned.
  • the mapping of the physical nodes on a logical tree is effected, from which procedure the root node and the various leaf nodes will be identified. By itself, this is a prior art procedure.
  • the root is activated; generally, this is done by the root node itself.
  • the root node sends a data packet to the next-following leaf node.
  • the root node detects the acknowledge packet received from the node that the most recent data packet had been sent to; furthermore, the root node figures out the return time. In effect, this block includes a waiting loop not shown for clarity.
  • the root node detects whether the return time so measured is larger than the lowest value of the two values that had been stored. If positive, in block 72 the new value is stored. If negative, block 72 is passed by. In block 74, the root node detects whether the most recent leaf node was the last one of the set of leaf nodes. If negative, the procedure reverts to block 66. If positive, the procedure goes to block 76, wherein the two highest return times are validated, and the gap_count is determined according to the expression given hereabove. Table 1 illustrates Static Gap Count Optimization Values. By themselves, these values have been known to persons skilled in the art.

Abstract

La présente invention concerne un procédé permettant de mettre en oeuvre un réseau multiposte de manière à y effectuer des communications noeud à noeud à travers un bus en série dans un mode sans collision, tout en faisant exécuter une procédure de numérotation de temps de silence à une station émettrice de communication, avant de lancer une telle communication, pour y mesurer un intervalle de repos, ledit procédé étant caractérisé par les étapes consistant à: mesurer diverses valeurs de temps de propagation entre un premier noeud et un second noeud; sélectionner une pire éventualité parmi lesdites valeurs de temps de propagation; affecter un numéro de temps de silence à ladite valeur de propagation de pire éventualité.
EP02700502A 2001-03-06 2002-02-15 Systeme, procede et noeud de mesure pour determiner une valeur de numerotation de pire eventualite dans un reseau multiposte Withdrawn EP1368934A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP02700502A EP1368934A1 (fr) 2001-03-06 2002-02-15 Systeme, procede et noeud de mesure pour determiner une valeur de numerotation de pire eventualite dans un reseau multiposte

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
EP01200841 2001-03-06
EP01200841 2001-03-06
PCT/IB2002/000472 WO2002071699A1 (fr) 2001-03-06 2002-02-15 Systeme, procede et noeud de mesure pour determiner une valeur de numerotation de pire eventualite dans un reseau multiposte
EP02700502A EP1368934A1 (fr) 2001-03-06 2002-02-15 Systeme, procede et noeud de mesure pour determiner une valeur de numerotation de pire eventualite dans un reseau multiposte

Publications (1)

Publication Number Publication Date
EP1368934A1 true EP1368934A1 (fr) 2003-12-10

Family

ID=8179974

Family Applications (1)

Application Number Title Priority Date Filing Date
EP02700502A Withdrawn EP1368934A1 (fr) 2001-03-06 2002-02-15 Systeme, procede et noeud de mesure pour determiner une valeur de numerotation de pire eventualite dans un reseau multiposte

Country Status (5)

Country Link
US (1) US20020176436A1 (fr)
EP (1) EP1368934A1 (fr)
JP (1) JP2004522339A (fr)
CN (1) CN1457577A (fr)
WO (1) WO2002071699A1 (fr)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7225286B2 (en) * 2002-06-24 2007-05-29 Koninklijke Philips Electronics N.V. Method to measure transmission delay between 1394 bridges
DE10322950A1 (de) * 2003-05-22 2004-12-16 Deutsche Thomson-Brandt Gmbh Verfahren zur Einstellung konsistenter Werte für einen Parameter in einem Netzwerk verteilter Stationen sowie Netzwerkteilnehmerstation für die Durchführung des Verfahrens
JP4302483B2 (ja) * 2003-10-28 2009-07-29 パナソニック株式会社 データ伝送方法およびデータ伝送装置
EP1865663A1 (fr) * 2005-03-29 2007-12-12 Pioneer Corporation Appareil, procede et programme de surveillance de communication, et support d'enregistrement
US20080056147A1 (en) * 2006-08-29 2008-03-06 Elliott Steven L Method and apparatus for determining minimum round trip times for a network socket
US20080056146A1 (en) * 2006-08-29 2008-03-06 Elliott Steven L Method and apparatus for determining maximum round trip times for a network socket
CN103197982B (zh) * 2013-03-28 2016-03-09 哈尔滨工程大学 一种任务局部最优检查点间隔搜索方法

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5875301A (en) * 1994-12-19 1999-02-23 Apple Computer, Inc. Method and apparatus for the addition and removal of nodes from a common interconnect
US5784648A (en) * 1995-12-01 1998-07-21 Apple Computer, Inc. Token style arbitration on a serial bus by passing an unrequested bus grand signal and returning the token by a token refusal signal
US6212171B1 (en) * 1998-06-22 2001-04-03 Intel Corporation Method and apparatus for gap count determination
JP2000013423A (ja) * 1998-06-26 2000-01-14 Sony Corp 情報処理装置および方法、並びに提供媒体
JP2002009796A (ja) * 2000-06-26 2002-01-11 Sony Corp データ転送システム及びデータ転送管理装置並びにデータ転送方法
US6766407B1 (en) * 2001-03-27 2004-07-20 Microsoft Corporation Intelligent streaming framework

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO02071699A1 *

Also Published As

Publication number Publication date
US20020176436A1 (en) 2002-11-28
WO2002071699A1 (fr) 2002-09-12
JP2004522339A (ja) 2004-07-22
CN1457577A (zh) 2003-11-19

Similar Documents

Publication Publication Date Title
KR101086981B1 (ko) 통신시스템의 마스터 스테이션과 액세스 제어 방법
US5355375A (en) Hub controller for providing deterministic access to CSMA local area network
JP3720345B2 (ja) 伝送装置
KR100646122B1 (ko) 버스 브리지에서 복수의 버스 노드들에 사이클 클럭을 분배하는 방법 및 장치
JP4112269B2 (ja) 複数のユーザが共有するネットワークにおいてデータ衝突を解決する方法
JPH09294128A (ja) 網動作方法、要求経路方法並びにルーティング及び承認制御する方法
Chlamtac An Ethernet compatible protocol for real-time voice/data integration
JPH10200583A (ja) ネットワーク接続装置
RU2598293C1 (ru) Способ и устройство для передачи стандартных данных конфигурации усовершенствованной системы выбора протокола передачи
US20020176436A1 (en) Method for in a multi-station network determining a worst case gap_count value, and a system and a measuring node arranged for implementing such method
US7688863B2 (en) Methods and apparatus for sharing network bandwidth
EP0605341A2 (fr) Appareil pour le couplage des boucles FDDI
US6473801B1 (en) System and method for arbitrating bandwidth on segmented network topologies
US7843942B2 (en) Node and fair rate calculating method
Anantharamu et al. Adversarial multiple access channel with individual injection rates
Ayar et al. A delay and throughput study of adaptive contention window based HomePlug MAC with prioritized traffic classes
KR100397718B1 (ko) 네트워크 로드 평가 및 이를 이용한 통신 네트워크에서의 응용 장치
KR20020095250A (ko) 멀티-스테이션 네트워크에서 최악의 경우 갭_카운트 값을결정하기 위한 시스템, 방법 및 측정 노드
WO2001086989A1 (fr) Procede d'attribution de canaux radio dans un reseau sans fil
US5941948A (en) Admission controller for network access
Sharon et al. A CSMA/CD compatible MAC for real-time transmissions based on varying collision intervals
WO2000076141A1 (fr) Procede de transmission de paquets de donnees et reseau heterogene destine a cette transmission
WO2009118648A1 (fr) Système réseau de réservation de plage horaire, procédé de transfert de trame, et dispositif réseau
JP4143881B2 (ja) ネットワークシステム
JP3891927B2 (ja) 通信機器およびネットワークシステム

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20031006

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20041115